Polyamideimide and polyamide amic acid resin polymers (hereinafter referred to as PAI) are well-known thermally stable polymers that are used for many high performance coating applications due to their excellent adhesion, temperature resistance, and high strength.
The primary route to synthesizing polyamideimide polymers in a form that is convenient for the manufacture of coatings is by reacting diisocyanate, often 4,4′-methylene diphenyldiisocyanate (MDI) with trimellitic anhydride (TMA). In this process, PAI polymers are typically manufactured in polar aprotic solvents such as N-methyl amide compounds including dimethylformamide, dimethylacetamide, N-methylpyrrolidone (NMP), N-ethylpyrrolidone.
However, with increasing regulation of certain materials and compounds, the solvents used in these polymerizations of the coating compound have recently come under scrutiny due to toxicological concerns. Thus, there is a need for generation of coating compounds that provide performance characteristics that are comparable to existing coating applications, while utilizing a safer solvent composition.